Peripheral nerve elongation by laser Doppler flowmetry-monitored expansion: an experimental basis for future application in the management of peripheral nerve defects.

Nerve grafting often fails to achieve optimal functional results and is always associated with donor-site morbidity. Peripheral nerve elongation by the use of a tissue expander may provide a useful adjunct in the management of segmental nerve loss. In the present study, rabbit sciatic nerve (n = 40) was elongated by expansion while nerve blood flow was monitored by laser Doppler flowmetry. Elongation was possible up to 40 percent with preservation of clinical nerve function. Nerve conduction velocity of the expanded nerves decreased in a linear relation to elongation. The reduction in nerve conduction velocity may be secondary to the observed widening of the nodes of Ranvier and altered membrane properties after remyelination. Demyelination and remyelination of whole internodes and axonal degeneration occurred only sporadically. Thus laser Doppler flowmetry-monitored expansion provides a safe method for elongation of intact rabbit sciatic nerve while nerve function and axonal continuity are preserved. Further studies are needed before clinical use is considered. This technique may represent a favorable alternative to nerve grafting for the treatment of peripheral nerve defects.

Peripheral nerve elongation by laser Doppler flowmetry controlled expansion: morphological aspects.

Peripheral nerve elongation by a tissue expander may offer an alternative to nerve grafting in the management of segmental nerve loss. We investigated the morphological changes in peripheral nerve following slow nerve elongation by laser Doppler flowmetry controlled expansion in a rabbit sciatic nerve model. The animals were randomly assigned to one of four groups, with an expander volume of 0, 5, 10 or 15 cm3, respectively. An elongation of up to 40% was possible with preservation of clinical function. Nerve conduction velocity decreased in relation to elongation. Paranodal widening, followed by remyelination of the node, were early and constant morphological features. Demyelination and remyelination of whole internodes, and axonal degeneration occurred sporadically and did not correlate with elongation, rate of elongation or neurophysiological parameters. The model of laser Doppler flowmetry controlled nerve expansion provides a method for remodelling of myelin sheaths and lengthening of nerve fibers without axonal damage.

Peripheral nerve elongation by laser Doppler flowmetry controlled expansion: functional and neurophysiological aspects.

A new method for elongation of peripheral nerves with preservation of function is presented. Nerve blood flow during experimental nerve expansion of rabbit sciatic nerve is controlled by laser Doppler flowmetry in order to avoid nerve ischemia. Using this method, nerve function in relation to gait remained intact in 72.5% of the animals and recovered within 3 weeks in the others. Disturbances in toe-spread reflex recovered completely in all animals after 3 weeks. Significant nerve elongation up to 40% is possible with preservation of function when nerve blood flow is controlled by laser Doppler flowmetry.

A model for monitoring nerve blood flow during expansion by laser Doppler flowmetry in the rabbit.

A new model is described for monitoring nerve blood flow during expansion by laser Doppler flowmetry. Rabbit sciatic nerve is gradually expanded with a custom-made spherical expander, while nerve blood flow is monitored by laser Doppler flow output. This model provides a valid method of controlling nerve blood flow during expansion.

Salvage of a through-knee amputation level using a free fillet of sole flap.

A young adult male sustained a compound crural fracture with a 15 cm defect of tibia and fibula, and an extensive soft-tissue loss of the lower leg and knee joint. A free fillet of sole flap was raised on the amputated foot and transferred to the soft-tissue defect around the femoral condyles in order to prevent an above-knee amputation. Intact vascularisation and sensation of the flap were secured by microsurgical anastomoses of the popliteal and posterior tibial vessels and the sciatic and tibial nerves. The patient was rehabilitated rapidly with a prosthesis. At the 12-month follow-up, he demonstrated excellent "foot" sensibility, stable soft-tissue coverage of the stump, and an optimal functional result.

[Subfascial lipoma of the forehead]. / Het subfasciale lipoom van het voorhoofd.

Three patients with subfascial lipoma of the forehead are presented. These deeply placed lipomas are seen in up to fifty percent of the lipomas of the scalp. A characteristic feature is the intact skin line pattern over the tumour. Surgical treatment involves incision of the aponeurosis of the M. occipitofrontalis.

Intraoperative and immediate postoperative management of calves undergoing valve or total artificial heart implantation.

The intraoperative and immediate postoperative management data were recorded in a series of twelve artificial device implantation operations in calves. Nine of these were valved conduit experiments not requiring cardiopulmonary bypass, and three were total artificial heart implantations in which bypass was needed. The intraoperative and immediate postoperative management procedures of this laboratory are described including anesthesia, respiratory and drug therapy, and cardiopulmonary bypass management. This paper shows how these procedures may aid in reducing the recovery times of research animals.